Source : Webster's Revised Unabridged Dictionary (1913)

Welldrain \Well"drain`\, v. t. [imp. & p. p. {Welldrained}; p.
   pr. & vb. n. {Well-draining}.]
   To drain, as land; by means of wells, or pits, which receive
   the water, and from which it is discharged by machinery.